Blade fastening device for saws



Aug. D. T. ANDERSON 2,089,105

BLADE FASTENING DEVICE FOR SAWS Filed April 2, 1936 Inventor By w Attorney Patented Aug. 3, 1937 BLADE FASTENING DEVICE FOR SAWS David T. Anderson, Montreal, Quebec, Canada, assignor to Harold C. A. Walby, Montreal,

Quebec, Canada Application April 2, 1936, Serial No. 72,310

4 Claims.

The present invention relates to blade fastening means for frame saws and the like.

An object of the invention is the provision of a saw having a blade fastening device'which is adjustable on the frame.

Another object of the invention is the provision of a saw having a blade fastening device designed so as to enable variation in the tension v of the blade and to counter-act decrease in the tensional effect of the frame.

A further object of the invention is the provision of a blade fastening device of the aforesaid character which may be employed on conventional saw frames and may be adjusted without the use of tools.

A still further object of the invention is the provision of a blade fastening means for saws whichv is relatively simple and durable in construction.-

Otherobjects and advantages of the invention will become apparent as the description progresses.

In the accompanying drawing forming a part of this specification and in which like reference characters are employed to designate corresponding parts throughout the same:-

Figure 1 is aside elevational view of a saw equipped with the improved blade fastening device,

Figure 2 is a fragmentary perspective view of the same,

Figure 3 is a fragmentary side elevational View of the saw frame showing the blade fastening device in section,

Figure 4 is a similar view showing the manner of releasing the device, and

Figure 5 is an enlarged sectional View taken on the line 5-5 of Figure 3.

Referring to the drawing, wherein for the purpose of illustration is shown a preferred embodiment of the invention, A generally designates a saw frame of the type commonly known as a bow frame used in conjunction with web or buck saws. The frame A may be formed of metal tubing, wood or the like, and is bent to indicated at B, mounted so as to be slidably adjustable on the frame arm I2 and engageable With one end of the saw blade. The device B which may be formed. of sheet metal or in any suitable manner embodies a body portion l5, 5- shaped to slidably embrace theframe'arm I12 and loosely conforms to the cross sectional contour of the arm. At the inner side, the body. is formed with 'a pair of parallel apertured complementary H arms I6 arranged in parallel closely spaced posi- 10 tion and disposed to receive therebetween one end of a saw blade H. A bolt I8- is adapted tobe fitted through the apertures in the arms 16 and through a registering aperture in the blade for releasably connecting the blade to the 15" arms. At the opposed outer side portion of the approximately loop-shaped body-l5is formed a tapered laterally projecting lip 29 having-a flat top surface for a purpose which will be later described. Y 26 At the top outer edge, the body l5 of the fastening device'is formed with a longitudinally extending relatively narrow and taper-ed tongue 2| :having a struck out or dented inwardly protruding boss 22 intermediate its ends. This boss 5 is designed to engage any one of a number of indentations .or cavities 23 formed at predetermined longitudinally spacedintervals on theframe arm on which the device is fitted.

The slidable device is releasably held in set 30 position on the arm by means of a fastening ring 25 loosely fitted on the frame arm and having an interior taper so that it may be slidably disposed over the tongue in order to press the tongue against the arm and more particularly 35 to retain the boss 22 of the tongue into a selected indentation 23 in the arm.

Thus, the device is initially disposed in such position on the arm as to fasten the saw blade at suitable tension on the frame for predeter- 40 mined work. If, for use in different Work, it is advisable to vary the tension of the blade, the fastening ring 25 is struck by the foot of the worker so that it is slid longitudinally on the arm in a direction away from the device and to 45 disengage the end portion of the tongue 2|. The device is then dislodged from its adjusted position by disposing the frame in an upright position and placing the foot on the lip 20. If the tension of the blade is to be increased, the weight of the body is placed on the foot held on the lip, so as to slide the fastening device 13 downwardly on the frame arm and toward the lower handle portion, as shown to advantage at Figure 4, and until the boss 22 enters the desired cavity 23 in the frame. The securing ring 25 is then slid downwardly to firmly compress the tongue against the arm and to secure the device in the set position.

Such adjustment of the device not only enables variation in the tensional mounting of the saw blade but is useful in counter-acting a loss or decrease in the tensional effect of the bow frame, enabling prolonged use of the frame which would be discarded with the fastening devices heretofore commonly used.

Furthermore, the construction of the device is such as to enable the same to be adjusted manually and without tools of any kind and also en ables adjustment in clearance of the saw, that is, in the space between the blade and the longitudinal portion In of the frame. The formation of the adjustable device is such as to retain the blade in proper alignment in the various adjusted positions.

As is readily apparent from Figure 1, one end of the blade I! is attached to the end of the short frame arm II by connection with a stationary pin 21 removably positioned in apertures in opposed sides of a bifurcated structure at the end of the arm. Consequently, the adjustment of the movable fastening device B on the longer frame arm l2 effects a pivotal movement of the blade with respect to the fastening pin 21 and avoids binding or distortion of the blade.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same, and that various changes as to the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. In a saw including a frame having a slanting end portion provided with longitudinally spaced cavities, a blade fastening device embracing the said arm and slidable longitudinally thereon, a projection on the device for detachably engaging one end of the saw blade, a boss projecting inwardly on the sliding device engageable with the respective cavities on the frame, a ring slidable to press a portion of the sliding device against the arm of the frame so that the boss will engage one of the cavities in the frame for releasably securing the device in adjusted position, and an outwardly projecting lip on said sliding device for adjusting the device on the frame.

2. A device of the character described comprising a saw frame having a slanting end portion provided with longitudinally spaced cavities, a blade fastening member slidably fitted on the said end portion of the frame, means on said fastening member for engaging one end of a saw blade, a tongue formed integral with the fastening member and normally extending substantially parallel with and alongside the end of the saw frame in both operative and inoperative positions of said tongue, a boss on the tongue engageable with the cavities in the frame, and means for releasably securing the said boss in a selected cavity.

3. In a saw including a frame having a slanting end portion provided with longitudinally spaced cavities, a blade fastening device embracing the said end portion and slidable longitudinally thereon, a tongue formed integral with the fastening device and normally extending substantially parallel with and alongside the end of the saw frame in both operative and inoperative positions of said tongue, a boss projecting inwardly from the tongue engageable with the respective cavities on the frame, and means for releasably holding the boss in engagement with a selected cavity for releasably fastening the slide member in adjusted position on the frame.

4. In a saw including a frame having a slanting end portion provided with longitudinally spaced cavities, a blade fastening device embracing the said end portion and slidable longitudinally thereon, a tongue formed integral with the fastening device and normally extending substantially parallel with and alongside the end of the saw frame in both operative and inoperative positions of said tongue, a boss projecting inwardly from the tongue engageable with the respective cavities on the frame, and a ring slidable to press the tongue against the end portion of the frame so that the boss will engage one of the cavities therein for releasably securing the device in adjusted position.

DAVID T. ANDERSON. 

